Norman mccaety



(No Model.)

N. MoOARTY.

ELECTRIC ARC LAMP.

N0. 310,837. Patented Jan. 13, 1885 NORMAN MOOARTY, OF HOOSAO, NE\V YORK,

PATENT OFFICE.

ASSIGNOR TO J. 13. TIBBITS,

OF SAME PLACE.

ELECTRlC-ARC LAMP.

SPEC'EFIOATIOI" forming part of Letters Patent No. 310,837, dated January 13,1885.

(No model.)

To all whom it may concern.-

Be it known that I, NORMAN McCiinrv, of Hoosac, in the county of Rensselaer and State of New York, have invented a new Improvement in Electric-Arc Lamps and I do hereby declare the following, when taken in connection with accompanying drawings, and the letters of reference marked thereon, to bear full,

clear, and exact description of the same, and' 1; which said drawings constitute part of this specification, and represent, in

Figure 2, a diagram showing the carbons, principal magnet, and shunt as in proper working condition, arrows denoting the direction of the current; Fig. 1, the same diagram, showing the armature of the shunt-magnet driven from its pole, and whereby the circuit is taken through the resistance-coils, arrows indicating the direction of that circuit.

This invention relates to an improvement in electric-arc lamps in which a shunt-magnet is employed, and in a system of several lamps on a single circuit, the object of the invention being to avoid the difficulty arising from imperfection in the mechanism of either lamp, whereby at any time the carbons in any one lamp shall fail to feed by causing the lamp not only to be automatically cutout when the feed is imperfect, but automatically cut in when the imperfection is removed, and at the same time maintain a balance between the outside circuit and the machine the same as if the defective lamp were in perfect operation; and the invention consists in the method and in 3 5 the combination of the devices hereinafter fully described, and particularly recited in the claims, whereby this object is accomplished.

For convenience of illustration I show the principal magnet, the Lshunt-magnet, and the 0 carbons detached from the usual mechanism of the lamp.

A represents the principal magnet, which is in connection with the feeding-carbon by any of the usual or known mechanism,whereby the carbon will be caused to feed.

B represents the lower or fixed carbon, and O the upper or feeding carbon.

D is a magnet composed of a core, E, with the armature F. The core is wound with a fine wire, as at a, in shunt-circuit in one direction, and a coarse wire, as at b, in main circuit in the opposite direction, similar to the winding of all differential magnets.

G represents the main-line wire, running to the principal magnet, A, but also in connection with a resistance-coil, H, leading to or in connection with the armature F. Below the armature F is a contact, I, from which a resistance-coil, L, is in connection with the wire M, leading to the next lamp. The armature is provided with apoint, N, which, when the circuit through the carbons is broken, rests upon the contact I, as seen in Fig. 1. From the main-line wire where the resistance-coil H connects a fine wire, d, leads to one end of the shunt-coil a, and from the other end of that coil a fine wire, 6, leads to the resistancecoil L. From the main magnet the wire 1 leads to one end of the coarse coil b,and thence, by a wire, 9, to the positive carbon C. The resistanceeoils H L are equal to or greater than the resistance of the are when the lamp is coldthat is, not working. The armature F is disengaged from its pole and the contact N rests upon the contact I. The current 7 5 then will be from the main line Gr through the coil H, armature F, contacts N I, coil L, to the wire M, leaving the main magnet and carbons cut out; but at the same time there is another course open to the currentthat is, So from the main line around the cut-out magnet D to the main magnet, thence to the positive carbon, to the negative carbon, thence off through the wire M. hen the circuit is closed, the current will divide at the point 8 5 where the resistance-coil H is connected, and in inverse proportion to the resistance, the larger portion following the line through the principal magnet and carbons. This will magnetize the core E, raise the armature F, and break the contact between N and I, and thus force the entire current through the principal magnet, which, by the usual mechanism, will form the are at the carbon points. Now, if through any defect in the mechanism the car- 9 5 bons fail to feed, the are will increase in length, forcing more and more of the current through the shunt-line (2 until its effect upon the core E is sufficient to neutralize the effect of the coarse wire.

Then the armature F will be ICO forced from its pole and make contact between N and I, thereby forming a new circuit around the lamp, instead of through it, at the same time throwing in a resistance, H L, equal to that of the are when burning, so that the effect on the machine under this condition is the same as if the lamp were burning. So soon as the cause of the obstruction is removed and the carbons come together, the current will again divide at the point where the resistance H leads from the main line, the armature F will be raised, as before, and throw the circuit entirely through the carbons.

Defects in feeding frequently occur in the best mechanisms; but generally they are such defects that after a short interval relieve themselvessuch, for instance, as the failure of the carbon to fall at the instant required; but after a short interval it will drop of its own gravity.

By my invention the lamp not only cuts itself out when imperfections in feeding occur, but cuts itself in when the imperfection or in terruption is overcome, at the same time k eeping up the balance between the outside circuit and the machine; or in some cases it may be used as a secondary feed by breaking the circuit through the carbons at such times as the main feeding device fails to work, causing the carbons to approach each other.

I claim 1. In an arc lamp, the combination of the principal or feeding magnet A, the magnet D, having its core E wound with fine wire and with an overlay of coarse wire, the coarse wire in the circuit through the principal magnet and positive carbon, the resistancecoil H. leading from the main line to the armature F of the magnet D, a second resistance-coil, L, between the contact I and the negative carbon, the armature F, provided with a contact, N, arranged to engage the contact I when said armature F is released from its magnet, one end of the fine-coil or shunt wire of the magnet D in connection with the main line, the other in connection with the second resistancecoil, L, substantially as described.

2. In an arc lamp, the combination of the principal or feeding magnet, a differential magnet, and resistance-coils between the main line and the negative carbon, outside the principal magnet, the circuit being through the armature of the differential magnet, substantially as described, and whereby said magnet and resistance-coils maintain a balance between the outside circuit and the machine, substantially as and for the purpose described.

NORMAN MCOARTY.

Nitnesses:

IV. '1. Bluzoock, NOBLE PrnLLirs. 

